Assuming the question refers to 55/66, the answer is 5/6
5 over 6
66/110=33/55=3/5
35/66 is in its simplest form.
28/55 is in its simplest form.
38/55 is in its simplest form.
42/55 is in its simplest form
55/64 is in its simplest form.
36/55 is in its simplest form.
54/55 is in its simplest form.
55/7 is in its simplest form.
9/55 is already in simplest form!
56/55 is already in its simplest form